Bumper end construction



Feb. 24, 1931. H, R. MCMAHON BUMPER END CONSTRUCTION Filed July 17, 1930Patented Feb. 251, 1931 UNITED STATES PATENT OFFICE HARRY R. MCMAHON, 0FCORAOPOLIS, PENNSYLVANIA, ASSIGNOR T0 STANDARD STEEL SPRING COMPANY, ACORPORATION OF PENNSYLVANIA BUMPER END CONSTRUCTION Application led July17,

This invention relates to bumper constructions and particularly to theend construction of bumpers of the single impact bar type.

Single bar bumpers hitherto used have aso called hinge constructionconnecting the front and rear members. In one type the front bar isslotted out at the ends and two eyes formed and an eye formed on therear bar is inserted therebetween, a pin being dropped through the threeeyes in known manner. In another type this construction is substantiallyreversed, a yoke being fastened to the back bar which in turn straddlesthe front bar, being fastened by a bolt. Both of these constructions,however, materially weaken the bumper at the ends due to the cuttingaway of the material of the bars and due to the fact that with suchconstructions every impact causes a shearing tendency on the bolts.

One of the objects of the present invention is to provide a single barbumper capable of withstanding great shoclr and in which all the membersare in mechanical balance.

Another object is to provide a bumper of the single bar type in whichthe ends are of neat appearance and capable of resisting shock equallywith the rest of the bumper.

A further object is to so associate and connect the bar ends that thebolt or pin passing therethrough is never subjected to shearing action,itsonly function being that of maintaining the members in position.

A still further object is to provide an end construction such thatfailure from shock cannot occur at that point and to provide aconstruction permitting thc varying of the width and thickness of eitherbar without detrimental effect.

In the accompanying drawings:

Figure l is a plan view of a bumper end construction embodying thepresent invention.

Fig. 2 is an elevational view of the same.

Fig. 3 is a section taken on the line III-IH of Fig. 1; and

Fig. 4 is a view similar to Fig. 3 of a modication.

In the accompanying drawings, the impact or front hum er bar 10 is, inthis case, the wider and thicer one and the rear bar 1l 1930. Serial No.468,614.

is the narrower and thinner one. It must be understood, however, thatthe proportions of these two bars may be varied in any desired manner sothat the front or impact bar l0 may be either thinner than the rear baror it may also be narrower depending upon the conditions that must befulfilled 1n any particular instance of use. Furthermore, bot-h bars, ifso desired, could be of the same width and of the same section.

As will be apparent, the front or impact bar l() is bent around at itsend so as to form a substantially cylindrical housing portion or member,which is hereinafter termed an eye or a cylinder.

For the purposes of explanation, it is only necessary to describe oneend construction, it being understood that the other end is identicaltherewith. This cylinder may be formed in any desired or suitablemanner, not forming a part of the present invention. The rear barsimilarly has a cylinder formed at its end, this second cylinder,however, being in the particular instance shown, a smaller one fittingwithin the first cylinder and being concentric therewith, the smallercylinder being, therefore, an inner cylinder relatively speaking. Thesetwo cylinders may be assembled in any desired manner such as byinserting the smaller cylinder axially of the larger in which it fitsproperly, the larger cylinder' being not entirely closed as will beclear from F ig. l, thereby allowin suitable relative movement of thebars under impact or stress.

The complete assembly of the bumper end construction is clear from Fig.3 and as therel shown lock washers 16 are placed above and below the.inner cylinder followed by suitable spacers 15, a bolt l2 being thenpassed through all the members, said bolt having an enlarged head 13 anda nut 14 on its lower screvw threaded end. A suitable lock washer 17with or without other washers is placed between the nut 14 andthe lowerends ot the members concerned. l

Figure 4 illustrates one modified form wherein the larger cylinder isformed of a bar 10 whose cross section is thinner than that of th'e bar1l forming the inner cylinder as will be understood from the foregoing.

The remaining elements are the same as those of Fig. 3 and furtherexplanation is, therefore not required.

Se n a construction as that set forth provides a bumper of the singlebar type which is capable of withstanding great shock and, moreover, sodoin without tending to shear the bolts connectingI the single impactbar with the rear bar. n addition, a construction is provided whereinthe end construction is as strong as1 any other part of the bumper andhence no weak point exists to shorten the life of the bumper. Theproportions and dimensions of the bars may be so chosen that the sectionmodulus is the same in both thereby maintaining the balance ofelasticity between the two. This constitutes an important advance and iseffected by using in the same bumper a front and rear bar whose relativethickness and width are appropriate, all conditions being considered.

While the. above is illustrative of preferred forms of the invention itis understood that various other modifications, changes, omissions orsubstitutions may be made without departing from the spirit of theinvention.

What I claim as new and desire to secure by Letters Patent is:

1. In a bumperconstruction, a front and a rear bar, the ends of saidbarshaving nest.- ing concentric eyes, and a bolt assembly passingthrough said eyes for maintaining said bars in position, said rear barbeing narrower than said Jfront bar, and spacers in said bolt assemblycompensating for the difference in' width of the bars.

2. In a bumper construction, a front and a rear bar, the ends of saidbars having nesting concentric eyes, and a bolt assembly passing throughsaid eyes for maintaining said bars in position, said rear bar beingnarrower and thinner than said front bar and lock washers and superposedspacers in said bolt assembly cooperating with said rear bar.

Y 3. In a bumper construction, a front and a rear bar, the ends of saidbars having nesting concentric eyes, and a bolt assembly passingvthrough said eyes for maintaining said bars in position, said front barbeing wider and thinner than said rear bar, and lock washers andsuperposed spacers in said bolt assembly cooperating with said rear bar.

4. In a bumper construction, a single irnpact bar having eyes at itsends, a rear bar narrower than said impact bar also having eyes at itsends, said eyes being concentrically assembled with the narrowerinternal of the wider, spacers on said` narrower eyes compensating forthe diderenee between the lengths of the eyes, and a bolt passingthrough the whole.

In testimony whereof, I have hereunto subscribed my name this 14th dayof July, 1930.

